This study is a linkage analysis of families with human prostate cancer. A paper published in Science in 1996 by this group indicates the possibility of linkage of a locus for prostate cancer to a region of chromosome 1. This has been followed up this year by intensive linkage analyses of additional families to markers in this region and in other regions that showed some mild evidence of linkage in the initial genome scan. Families have been obtained and genotyped from several regions of the United States, Finland and Sweden. Efforts are also underway to develop additional family resources for this project. A second locus on the X chromosome has been mapped by linkage analysis in this fiscal year with results published in Nature Genetics, 20:175-179 (1998). These investigators have also joined a national Prostate Cancer Linkage Consortium to try to localize prostate cancerloci more rapidly. This project to identify and clone genes for prostate cancer is ongoing.